1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method for displaying an image to an observer.
2. Description of the Related Art
In a display device referred to as Micro Display such as a compact liquid crystal panel or an organic electroluminescence (EL) display, an apparatus that allows the observer to observe a virtual image by using a magnification optical system has been developed. This apparatus is used for an electronic viewfinder (EVF) that checks a frame taken by a video camera or a digital camera, or enables focus adjustment.
In recent years, in order to perform focus adjustment with the electronic viewfinder in an image pickup device at higher resolution, higher definition of the display device has been developed for the electronic viewfinder. Since the display device has become smaller in size and higher in definition, a good quality image can be provided even when a magnification rate is increased and the observer wants to observe a large image. In addition, an angle of view of an image observed by the electronic viewfinder tends to be larger.
In an apparatus such as an electronic viewfinder that displays an observed image, if an angle of view of the observed image is large, a certain area of the observed image may form an image in a blind spot position of the observer, generating an area unrecognizable by the observer in the observed image. For example, in a conventional electronic viewfinder, an angle of view of one eye is about 12°, and hence a blind spot located at about 15° causes no issue. However, a blind spot may become an issue in an electronic viewfinder that has an angle of view larger than 15°.
Especially, in a viewfinder of the video camera or the digital camera, if an intrusive object enters an area corresponding to the blind spot after the observer has determined a frame to be taken, the observer loses the intrusive object. As a result, an image unintended by the observer may be captured.
As a conventional technology that takes a line of sight of the observer into account, Japanese Patent Application Laid-Open No. 08-223468 discuses a technology for detecting a line-of sight direction of the observer, and changing a capturing range according to the line-of sight direction of the observer. However, in the technology discussed in Japanese Patent Application Laid-Open No. 08-223468, when an image of a large angle of view is observed, there is a possibility that the observer may lose an intrusive object displayed in a position corresponding to the blind spot.
As a conventional technology that takes the blind spot of the observer into account, Japanese Patent Application Laid-Open No. 11-174986 discuses a technology for displaying a low-quality portion of an image in the position corresponding to the blind spot of the observer. However, in the technology discussed in Japanese Patent Application Laid-Open No. 11-174986, while the image observed by the observer is changed based on the blind spot of the observer, an oversight caused by the blind spot of the observer cannot be prevented.